Student Development & Recruitment
Promoting Global-minded Professionals

Lia A. Stanciu

Chemical & Materials Science Department

Research on Aluminum Titanate Ceramics

Women researchers in the Chemical Engineering&Materials Science Department at UC Davis gained an important recognition in the scientific community. They are involved in high-level scientific projects and gain hands-on experience on state of the art equipment.

Among graduate and postgraduate student population in the Materials Science Department, majority are men, but there are also a few women who bring a very important contribution to scientific environment in the Department. They work on various projects, each in her narrow field of research but have a lot in common in terms of hard work and creativity.

Today is an exciting time to be doing research in nano materials field. Field Assisted Sintering is a novel technique that combines high heating rates and electrical current application to obtain final dense parts with the retention of the nano-structure of the precursors and is extensively used in the Materials Science Department. The technique is useful to get to final materials retaining small size, high surface area and unique properties of nano particles, which are to gain a performance advantage in a whole array of applications - coatings, catalysts, medical diagnostics, precision polishing, optical communications- to name only a few.

The UC Davis graduate student, Lia A. Stanciu, focuses her research on aluminum titanate ceramics.  Aluminum Titanate arose interest among scientists due to a combination of unique properties, such as a high melting point and a low thermal expansion coefficient.  This combination makes it suitable for a range of applications in the automotive, semiconductor, aeronautical and military industries.  However, problems of low mechanical strength and difficult sintering ability seriously limit its use. The graduate students' approach is to use amorphous nano sized precursors together with FAST (Field Assisted Sintering) to reduce the grain size, improve the sinterability and lower the formation temperature of aluminum titanate. The primary methods for achieving these objectives of the Project are: interrupted sintering experiments followed by scanning electron microscopy observations in the backscattering mode, which, together with X-ray analysis, can provide evidence of the phases present in the material and their orientation; studies on the effect on different heating rates on aluminum titanate properties; research on the effect of additives on stability and sinterability of aluminum titanate ceramic materials. The body of this research project has been published in the Journal of the American Ceramic Society (2001),  84(5),  983-985and has also been presented at several scientific meetings.

To name another scientific project, where women researchers play an important role, we must signal a new type of nanotechnology-based biosensor of supported bilayer assemblies that is under research in the Chemical Engineering Department. The technology could potentially be used, for example, for local sensing (e.g. in micro-array format) of biological toxins and local screening of antimicrobial agents.

Lipid bilayer-based sensors originally drew interest because the surfaces at which recognition processes take place in nature are lipid bilayer-based cell membranes where biological receptors are anchored with recognition element exposed to the aqueous surrounding. Lipids conveniently self-assemble into lipid bilayer capsules known as vesicles. These vesicles can be fused to surfaces ("vesicular deposition") to form a supported lipid bilayer of thickness approximately 4 nm.  This is of great convenience for sensor and screening formats where, in general, thin films are preferred since thin films can be conveniently interfaced with optical, electronic, mechanical and other devices.

UC Davis postgraduate researcher Ruxandra Vidu, is actively working on the project, and together with her co-workers, have found by atomic force microscopy (AFM) and electrochemical methods that tailoring the support surface with self assembled monolayers of different chain sizes and using mixtures of negatively charged and zwitterionic/neutral lipids can control the insulating properties of the lipid bilayer.  The results show that the polyion/alkylthiol supported lipid membrane system constructed in their work can be used not only as a biosensor for the detection of biomolecules with different properties, but also as a potential tool for the study of the structures and mechanisms of functional antimicrobial and antiviral drugs. The work is published in Langmuir, 18 (2002) 4, 1318-1331.